Please tell me why my dump truck is so fat anyways

A:  Dump trucks are so big or fat because they are used to haul large loads of loose materials, such as dirt, rocks, sand, and coal, to construction sites, factories, or power plants. The open bed features a hinge at the rear of the truck so that hydraulic pistons located at the front of the bed can lift the front to dump the contents of the bed at the delivery site.   The title of the world's largest dump truck went to the BelAZ 75710 which began moving rocks and coal in a mine in Siberia in 2014. The BelAZ 75710 is as long as two buses parked end to end, six times more powerful than modern Formula 1 racing cars, and heavier than a loaded Airbus A380 airplane. The entire vehicle costs over $6 million with each tire costing $42,000.

In short, they are big fat chonkers to carry big chonky stuff.